HD 122430 is single star[6] in the equatorial constellation of Hydra. It has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of 5.47.[2] The star is located at a distance of 105.6 light years from the Sun based on parallax.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 14h 02m 22.78173s[1] |
| Declination | −27° 25′ 47.1992″[1] |
| Apparent magnitude (V) | 5.47[2] |
| Characteristics | |
| Spectral type | K2–3III[3] |
| B−V color index | 1.331±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | −0.61±0.24[1] km/s |
| Proper motion (μ) | RA: −31.861±0.259[1] mas/yr Dec.: −4.195±0.215[1] mas/yr |
| Parallax (π) | 7.3651 ± 0.1407 mas[1] |
| Distance | 443 ± 8 ly (136 ± 3 pc) |
| Absolute magnitude (MV) | −0.17[2] |
| Details[4] | |
| Mass | 1.62±0.19 M☉ |
| Radius | 21.20±2.06 R☉ |
| Luminosity | 189.6±4.2[1] L☉ |
| Surface gravity (log g) | 1.96±0.07 cgs |
| Temperature | 4,383±19 K |
| Metallicity [Fe/H] | −0.08±0.04 dex |
| Rotational velocity (v sin i) | 2.59±0.45 km/s |
| Age | 1.98±0.67 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K2–3III.[3] It has completely run out of the hydrogen fuel that keeps it stable, although it is only two billion years old,[4] younger than the Sun's 4.6 billion years. HD 122430 has a mass of 1.6 times and radius of 22.9 times that of the Sun.[4] Despite its younger age, it has slightly lower metallicity, approximately 90%. It is radiating 190[1] times the luminosity of the Sun from its photosphere at an effective temperature of 4300 K.[4]
A candidate exoplanet was reported orbiting the star via the radial velocity method at a conference in 2003, and designated HD 122430 b. It has an orbital period of 0.94 years and an eccentricity of 0.68.[7] However, a follow-up study by Soto et al. (2015) failed to detect a signal, so it remains unconfirmed.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | >3.71 MJ | 1.02 | 344.95±1.08 | 0.68±0.09 | — | — |
See also
editReferences
edit- ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ a b Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode:1982mcts.book.....H.
- ^ a b c d Jofré, E.; et al. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931.
- ^ "HD 117207". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-23.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ a b Setiawan, J. (October 2003). Planets around evolved stars. Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22–25 April 2003, Heidelberg, Germany. Vol. 539. Noordwijk, Netherlands: ESA Publications Division. pp. 595–598. Bibcode:2003ESASP.539..595S. ISBN 92-9092-849-2.
- ^ Soto, M. G.; et al. (August 2015). "RAFT - I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra". Monthly Notices of the Royal Astronomical Society. 451 (3): 3131–3144. arXiv:1505.04796. Bibcode:2015MNRAS.451.3131S. doi:10.1093/mnras/stv1144.